International Dredging Review

International Dredging Review

Damen Dredging is introducing a new-concept dredge design for mining sand far offshore and in deep waters.
Mark Winkelman will describe the dredge in his paper New Approach for Deep Sea Dredging which he co-authored with E. van Duursen at the Texas A&M (TAMU) Seminar on Monday June 6.

The RoRo Deep Dredge can dredge up to 200 meters (656 feet) deep in the open sea and was designed to meet this demand and to challenge existing technical limitations.

In the RoRo Deep Dredge installation the dredging equipment has been separated from the storage and transport facility of the mined sand. A flexible suction pipe makes the system compact allowing a varying dredging depth that is independent of the vessel’s length.

The installation consists of a submersed excavation unit which includes a drag head and a dredge pump. A hose is connected to the unit and runs to a storage reel on deck. The flexibility of the system is evident as the hose can be rolled on and off the reel to adapt the dredging depth – hence the name RoRo Deep Dredge.

On deck the dredge piping connects the reel to discharge spreaders. Barges sailing alongside are filled continuously. As a result the dredging process is a continuous one boosting the efficiency of the dredging gear. No sailing time is required for the dredging gear thus idle time is sharply decreased.

Because the operating time of all equipment involved has been maximized the profitability of investments is increased. Another important advantage is that the modular dredging system can be temporarily mounted on a commonly available vessel resulting in a relatively minor investment and a shortened return-on-investment time.